Socket for electric discharge lamps



July 24, 1951 G. c. SALNEU 2,561,954

SOCKET FOR ELECTRIC DISCHARGE LAMPS Filed Jan. 28, 1947 v 2 Sheets-Sheet l INVENTOR.

GEORGE C. SALNEU I BY 4 W ATTORNEY July 24, 1951 G. c. SALNEU SOCKET FOR ELECTRIC DISCHARGE LAMPS 2 Sheets-Sheet 2 Filed Jan. 28, 1947 INVENTOR.

GEORGE C. SALNEU FIG. I3 38 ATTORNEY Patented July 24, 1951 UNI TE D .S'TATE'S PA-T EN T O FF I C E -,SOCKET;:FOR;ELECTRIC DISCHARGE LAMPS 'George' cii'salneu, Havertown, Pa.

Application January. 28, 1947, Serial No. 724,764

4"Claims. (01; 173 -328) The invention relates to sockets vfor electric .discharge lamp terminations. and, more particularly, .tocompression spring contacts for. .such sockets.

.Heretofore, sockets for electric .discharge lamp terminationsvhave been provided with guarded contacts comprising compressible helicalsprings positionedin the sockets inspaced relation from the socket mouth. ,Itis possible for. such. springs to :become-welded to the termination contacts, of high-voltage lamps and on removal of thelam-p to be. elongated or pulledoutintoa positionwhere they constitute anelectric shock hazard to {maintenance personnel. This ,conditicinwmight also occur with the vspring contact .of the .luminaire socket described in my copending patent application, Serial No. 664,148, ,filed-April23, 1946, now United States Patent No. 2,486,497,.issued Novemher 1, 1949, for a termination.ior-electric discharge lamps, in' which the springis engageable with a recessedcontact in the lamp termination.

The primary object of my invention is v to provide an electric discharge lamp socket in which this defect is overcome.

Another object of my invention is to :provide an. electric discharge lamp socket having, aresiliently depressible contact member of restricted extensibility constituting. aguarded contact, having a fixed minimum depth from the-mouth .of the socket.

' A further-object of my invention .is to produce an-electric discharge lamp sockethaving-a helical compression spring contact -:member ,provided with means incorporated .in thecontact member and co-operative withan element at its base for limiting its expansion.

.Stillanother object ofmy invention is to providean electric discharge lamp socket with .a helical compression spring contact memberhaving inexpensive, simple, durable andeffective means for limiting expansion toapredetermined length while permitting a desired degree of collapse.

With-these .and other objects in view =-which will .appear from the .ensuing description and claims, 1 the followingsets. forth, specific embodiments of my invention which ;;are-;described as examples and illustrated in the accompanying drawing, in -which- 7 Fig. 1a is :afragmentaryview, partlyin section; of, the electric discharge lamp luminaire-socket of my invention and the. associated lamp termination.

Fig. 2.:is ,anenlargedview of the helical'sprin'g of the: socket ofv Fig-:1. I

Fig. 3 is a fragmentary perspective view of thespring of Fig- 2 showing details of the construction of the top part.

.Fig. 4 isa fragmentary perspective view ofthe spring of Fig. 2 showing details of the construction at thev bottom. i v

Fig. ,5.,is a side elevationv of the upright hook member of the socket ofFig. 1. 1

Fig. 6 is a fragmentary side elevational viewcf parts of the socket of Fig. 1, showing .detailstof assembly.

Fig. 7 isa side elevational view ofa modification shown in extended position, of the. springand elongation restricting means.

. Fig. 8 is .a. side elevational-view of: the device of; Fig. 7, with thespring-in .partially collapsed position,,,sho wing details of construction.

I ,Fig. ,9 isa sideelevational view .of afurther modificationnf the spring and restraining means, with the spring shownin extended position.

.Fig.,.1.0..is a vside-elevational.view of another modificationcf the spring, .shown inv fully .extended position.

Fig.. 1 1 vis a. side .elevational view of the spring of Fig. 10, .shown assembled to. the .mounting screw and compressed towardit'.

V -Fig. 12is.-a fragmentary side elevational view partly in section, showing the device of Fig. 11, aslit would appear. after relieving the compression.

Fig.,.13 is-a fragmentary perspective view of the-.bodygof .thesocket ofFig. 1,showing--the spring mountingplate in assembled position relativetothe body.

.Figs..14 and ;15 are fragmentary sectionalelevationsvof .another modification of my electric luminaire socket showing alamp termination respectively justmaking contact withand fully depressed within. the-socket. I I

Fig. 16 is a developed plan view of thespring of Figs. 14 and 15. k

Referring. tothedrawing, I have shown in Fig. 1..one.endv of a high-voltage cold-cathode type lamp having-atermination. l5, comprising-ainbularglass shell I6, enclosing a metallic disk contactbutton. I1, wires [8 welded to an elec .trode l9an-d the contact ILanda glass sealing bell.,20. The bell 20 has acuppedrecess Zland ringwsealed to'the outerend 22 0f-the glass .shell 16. The termination 15 is engageable with a female. bodyror. socket, 25 which is, of'generally conventional type I having .91. substantially cylindrical hollow body'26 -.of glass'or other electric insulatingmaterial provided with screw; threads 2''! to-aengage av threaded, metal collar .528 for mounting in a luminaire (not illustrated). How= ever, I have replaced the large-diameter helical contact spring of the receptacles presently available with a helical contact spring 36 of diameter small enough to enter freely the recess 2| of the bell 20 and engage the contact H.

The spring 3|! projects freely from the base of the body 26, without external obstruction, and is mounted coaxially therein by means of a screw 3|, spring mounting plate 32, retaining plate 33 and nut 34. A lead 35 to an electric circuit, not illustrated, is attached externally of the body 26 to the screw 3| by the usual nut and washer means. The screw 3| is of the carriage-bolt type non-rotatably attached to the body 26 by having its tapered square neck 36 engageable in a square hole 3'! in the mounting plate 32 which is provided with depending flanges 36 adapted to engage the slotted bottom opening 39 of the body 26. The lower part of the screw 3| passes through a drilled opening in the retaining plate 33 which is of elongated shape adapted to pass through the opening 3.; when its longer axis is aligned therewith and to obstruct such passage when positioned at right angles thereto. The assembly of screw 3|, mounting plate 32, body 25 and plate 33 is held firmly together by tightening the nut 34 which engages the screw 3| below the plate 33. Projections 4!) on the upward side of the plate 33 prevent rotation thereof by engaging the outer side rim of the slotted opening 39.

The spring 38 is formed of resilient wire of requisite stillness to maintain its central position and engagement with the contact I], and is of generally helical shape tapering slightly toward the top. At the top 45 the wire is formed into a transverse-plane inward spiral for approximately a complete turn, then extends straight downwardly for approximately half the desired extended length of the spring, then describes a U- turn, and finally extends straight upwardly to terminate just short of the top 45, thereby forming a downward hook member 46. At the bottom 41 of the spring 36 the wire is spiralled inwardly to a circular arc of somewhat less than a complete turn, concentric with and perpendicular to the axis of the spring, and engageable with the neck 36 of the screw 3|.

An upright hook member 48 comprises a wire similar to that of the spring 30 formed into an open ring 49, which may or may not be flattened as illustrated and is engageable with the neck 36 of the screw 3 I, then bent sharply upward at the point 50, and finally bent into an inverted U- shape with a sharp curve 52 at the top and terminating with its end 53 a short distance above the ring 49. Between the bend 50 and the top 52, the wire is provided with an inflected curvature so that it may pass between the two bottom end turns of the spring 36 as will be presently described.

The spring 30 and hook member 48 are assembled to the screw 3| in the manner illustrated in Figs. 2 and 6. The hook member 48 is first assembled to the spring 36 with its loop 5 52 engaged by the downward hook 46, which is readily accomplished by fully compressing the spring 38, and with its ring 49 disposed beneath the end turn 41. In this condition the relation of the parts is such that the spring 39 is under slight compression. The spring 30 and the hook members are so arranged that when the lateral openings in the ring 49 and end turn 41 are aligned to atinghooks 46 and 48 will lie in mutually perpendicular vertical planes and the curvature 5| will clear the inside of the widest part 54 of the second turn from the bottom of the spring 30. The ring 49 of the hook member 48 is adapted to receive the neck 36 of screw 3| with a snug fit and permit clearance of the head 55 inside the upward bend 50.

The assembly of spring 30, hook member 48, mounting plate 32, retaining plate 33 and nut 34 loosely attached to screw 3|, is dropped screw foremost into the socket 25. The bottom of the body 26 is smoothly curved toward the slot 39 so that the nut 34 and retaining plate 33 drop through the slot 39, and the mounting plate 32 guided by the flanges 38, comes to rest in transverse locking position as illustrated in Fig. 13. It is then a simple matter to turn the plate 33 to transverse locking position, center the assembly in the slot 39, and tighten the nut 34 to obtain the desired rigidity. Because the end 53 of the upright hook member 48 is in close proximity to the head 55 of the screw 3|, and the free end of the downward hook member 46 terminates just short of the top of the spring, it is practically impossible to completely separate the hook members even when the spring is deliberately compressed to the limit.

It will be noted that the electric contact button I! is longitudinally recessed in the mouth of the lamp termination to a depth greater than the diameter of said mouth, and similarly the outer end 45 of spring 30 is at all times maintained at a depth from the open end of the body 26 greater than the diameter thereof.

The operation of the device is as follows. With the parts disposed as illustrated in Fig. 1 with the spring 36 under slight compression, the termination I5 is inserted into the socket 25 until the end 22 touches bottom in which position it is arranged to be held by the usual external clamps or ties (not illustrated). As the termination is moved into the socket, the bell 20 engages and moves down over the spring 30. Well before the end 22 reaches the bottom of the socket, the contact button I! meets the top turn 45 of the spring, after which further movement merely compresses the spring causing the hook members 46 and 48 to slide along each other. The spring and termination are so proportioned that the spring is not compressed to its limit when the end 22 of the termination comes to rest in the bottom of the socket. On removing the termination l5 from the socket 25, the spring 30 expands until the hook members 46 and 48 re-engage at the predetermined desired spring length.

Figs. 7 and :8 show a modification of my invention in which a spring 66 is restrained by a flexible pigtail 6!. The spring 60 is similar to the spring 36 except that it is brought to a plane turn at the top as a seat for a metal button 62 having an apertured shank B3 and a flat top comprising the electric contact. The pigtail 6| is looped through the aperture or eye of the shank 63 and both ends passed down inside the spring 60 and brought out between its last two turns at the bottom. The ends of the pigtail are then inserted into the hollow end 64 of a compressionconnector type lug 65 and suitable compression is applied to make a permanently tight connection. The lug 65 has a ring 66' adaptedto fit the neck 36 of the screw 3|, and a relatively long shank 61 which is bent up and inwardly to clear the head 55 of the screw 3|. In assembling this device, the spring 66 is compressed as shown in Fig. 8 while the lug 65 is being attached to the ends of i-etbe gpigtail ,6] after which the is raeleased. 'I 'he assembly then appearsas illustrated Fig.4? withthe spring 60 underslighticompression. To .attach .to the screw-3f| the spring. is

ring 66, thenslipped-sidewiseinto. thebottom end turn 61 ,of the. spring .60. The assembly 31911711311 attached to the socket; 2-5,- as gpreviously outlined ,Themodification:illustrated-in aa issiaar ever, .-in this .case the springifl, .d-i-fiers, the

acompressed; as in Fig.8, the screweinserted-dnsthe 5 'a-springs6llinhaving thetopendspiralledinwamdly '.-contact r1;! as;.illustratedrlnlftig.j14.,anil depressed iand:.-then turned'downwardly .as inspringdmbut "bay om h non hf l spi de cy -tcrminating at the lower-end-in an 65 511. 'The pigtail 12 is looped through .the eye ligand then connected: to the lug 65- as inthe-aznodificatio .ar gs. -10 to 12,- inclusive, iillustrate -ja'.-.*further ymodification which has-a spring.-80.,--similarato the spring 1-0, but in which the-wire tzl --:descending from the "top is :axially disposed; .and, with-the -springin unstressed "condition, extends through :2 wand-past the bottom end-'82 thereof. Theascrew 8310f device is similar 1150 :the screw .31 I except then 1 continues throughthe screw with a bore-.335 of considerably enlarged diameter. The :Wirei'BII is inserted into the bore 84 of the screw 83 which is then slipped sidewise into the bottom end turn 82 of the spring 80. Thespring 90 is then fully compressed so that the wire 6| protrudes below the screw 83 and a bead or enlargement-.86 "is formed at the end .of .thewire-fll .by swaging,

melting, bending over, flattening or the like. The

bead is freely movable in the bore 85, but'is too -la-rge'toenter the bore 84--and has its Qpedges rounded to preventbinding at the juncture'of the bor'e=85 with the bore-84. When the spring is released from the compressed positionshown'in:

Fig. 11, it expands and draws the bead "86 up through the -bore-95 untilthebead is stopped hy the constriction at the juncture'with the bore84 as illustrated in Fig. 12. The bead 86 is formed at such relation to the length of the wire 8| to give the desired length and slight compression of the spring 89 when in the released position. The device of Fig. 12 is assembled to the socket 25 in the manner previously described for the modification shown in Fig. 1.

Figs. 14 to 16, inclusive, illustrate another modification of my invention in which the helical spring is replaced by a bayonet contact member 90. The bayonet 90 is brazed, riveted or otherwise securely attached, both electrically and mechanically, to the midpoint of and perpendicular to a fiat spring 9|. The spring 9| has widened ends 92 and 93 transversely slotted in opposite directions to receive theneck 36 of the screw 3|. The spring 9| is bent into oval shape with the slots in the ends 92 and 93 in register, and the ends 92 and 93 are sprung sidewise to admit the neck 36. On releasing the ends 92 and 93 they spring back to enclose the neck 36. The spring 9| is then assembled on the screw 3| to the body 26 with the mounting plate 32 and retaining plate 33, as illustrated in Fig. '14, with the bayonet 90 firmly disposed in upright central position within the body 26.

As the termination I5 is depressed within the socket 25, the bayonet 90 is first engaged by the forft hesejparts Tto becomeweldedtogether. It'will be observed'thatin all examples o'ithe invention'illustrated' and described her'e'inthe safety, means "for. limiting the extensibility of the resilient COIT taCtTZmEIflb'BI are incorporated in said gneniberyand. "include one. or more *elewhicharetco-pperative with an element at base oi'ithe socket. "I-husthe 'resihentconta'ct :nrember projects freely, without external obstruction, permitting guarded "telescopic engagement between the .lamptermination and the socket, and insuring that such ficontactfwill [be maintained. at a; predeterminedminimum spacing "from the mouth "of'the body within which it is housedg it; Will'bG'ffllSO observed that inall oi the examples'fof the invention illustrated and-described 'herein 17a component 'of-the resilient contact or ffth'esccket, eitherthe spring itself or a stop ele- .m'ent-associated with;it, 'serves tojlimit it's exltensibility .and 'maintainpthe free end of the r .silient contact at a "depth from the. o en end ,of the socket not less than the diameter thereof. In all of the illustrated examples with the exception lof the'formof the invention shown in Figs. 14, 15, and I6 thespring'is of ahelical type and has .zincorporated within its-convolutions a stop element"fonthusflimiting its extensibility. f "In thmannexed tilrawin'gs I have disclosed. several species .of thelin'vention whereinthe elongated stop piece for .limiting the longitudinal rnovfem 'ent.of the contact element .is itse1'f;gen-

erally longitudinally movable within the female body, such stop piece being illustrated in the form of the hook 46 of Fig. 2, the pigtail 6| of Fig. '7, the hook H and pigtail 12 of Fig. 9, the wire 8| of Fig. 10, or the resilient arms of flat spring 9| of Fig. 14. However it will be appreciated that the invention comprehends the substitution of equivalent stop elements serving to limit the extent of longitudinal movement of the contact element within the female body, and the con-- nection of such stop means to the contact element and a fixed base in equivalent ways, all within the spirit of the invention as defined in the appended claims.

Although the invention has been described in considerable detail, such description is intended as illustrative rather than limiting, as there will be evident to those skilled in the art other embodiments and obvious modifications in construction and arrangement of parts, without departing from the spirit of the invention.

I claim:

1. In a socket for an electric discharge lamp termination having an electric contact, a female body of insulating material for receiving the termination, a guarded electric contact within said body including a helical compression spring with its base fixed to the bottom of said body, said spring to a length less than the internal depth of said body and to maintain it in recessed position Within said body when said termination is removed from said body. v 4' 2. In a socket for an electric discharge lamp having an electric contact, a female body of insulating material for receiving the termination, a guarded contact within said body including a helical compression spring longitudinally disposed within and fixed to the bottom of said body in spaced relation to the sides thereof, said spring being engaged and compressed by said first mentioned contact when said termination is pressed into said body, and said spring being provided at its free end with a generally axial hook disposed within said spring and directed toward the fixed end, and a hook member fixed to the bottom of said body and disposed generally axially within said spring and slidably engaged with said hook,

said hook and said hook member being main-,

tained in interlocking relation with each other and being mutually engageable and of a combined length less than the internal depth of said female body to limit the expansion of the spring to a length less than the internal depth of said body when said termination is removed from said body, and to maintain the free end of the spring at a fixed minimum depth from the mouth of said body.

3. In combination, an electric discharge lamp,

termination having an open mouth at the end thereof and a guarded electric contact member longitudinally recessed in the ,mouth of said termination and fixed at a depth therein not less than the diameter of saidmouth, and a socket comprising a female body of insulating material,

within which said termination fits, a guarded resilient contact including a spring fixed to the base of said body and projecting freely from the base of the socket towards the mouth thereof and yieldably movable longitudinally within said socket, the resilient contact extending into the recess of said termination to engage said contact member, elongated stop means connected to said resilient contact and engageable upon the base of said body to limit the extent of said longitudinal movement of the resilient contact, said elongated stop means being of such length as to maintain said contact at all times at a depth from the open end of said body not less than the diameter thereof.

'4. In combination, an electric discharge lamp termination having an open mouth at the end thereof and a guarded electric contact member longitudinally recessed in the mouth of said termination and fixed at a depth therein not less than the diameter of said mouth, and a socket comprising a female body of insulating material within which said termination fits, a guarded electric contact within said body including'a helical compression spring fixed to the base of said body and projecting freely from the base towards the open end thereof, the spring extending into the recess of said termination to engage said first mentioned contact member, a longitudinally extensible elongated stop element extending from the free end of said spring, axially disposed therein and fixed to the base of said body, to maintain the free end of said spring at all times at-a depth from the open end of said body not less than the diameter thereof.

' GEORGE C. SALNEU.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 715,647 Dunnegan Dec. 9,1902 1,711,300 Ziegler Apr. 30, 1929 1,753,179 Wertz Apr. 1, 1930 1,896,365 McClelland Feb. 7, 1933 1,942,724 Nelson Jan. 6, 1934 2,099,610 Ledder Nov. 16, 1937 2,152,558 Montroy Mar. 28, 1939 

